Daylight developing tank for photographic roll films



N. WOLFF Dec. 4, 1951 DAYLIGHT DEVELOPING TANK FOR PIV-IOTOGRAPHIC ROLL FILMS FiledOct. '10, 1947 INVENTOR. NATHAN WOLFF ATTORNEY Patented Dec. 4, 1951 UNITED STATES PATENT OFFICE DAYLIGHT DEVELOPING TANK FOR PHOTOGRAPHIC ROLL FILMS Nathan Wolff, St. Louis, Mo.

Application October 10, 1947, Serial No. 779,149

2 Claims. 1

This invention relates in general to certain new and useful improvements in daylight developing tanks for photographic roll films.

It is the principal object of the present invention to provide a photographic developing tank in which the entire developing process, inclusive of the steps of immersin the film in developing solution, the subsequent washing of the film, and the fixing and final washing operations, may be conducted under full daylight conditions.

It is a further object of the present invention to provide a developing tank of the type stated which can be quickly and conveniently loaded in any darkened place, such as a closet or the like, and can be accomplished with ease and speed.

It is a further object of the present invention to provide a simple and compact form of daylight developing tank which is rugged and durable and is economical both in cost of manufacture and in use.

With the above and other objects in view, my invention resides in the novel features of form, construction, arrangement, and combination of parts presently described and pointed out in the claims.

In the accompanying drawing Figure l is a front elevational view of a day light developing tank constructed in accordance with and embodying the present invention;

. Figure 2 is a top plan View of the photographic developing tank;

Figure 3 is a front elevational view of the cap or closure member forming part of the present invention;

Figure 4 is a bottom plan View of the cap 01' closure member;

Figure 5 is a vertical sectional view of the cap member taken along the line 5-5 of Figure 4;

Figure 6 is a front elevational view of the filmholding member with a length of narrow film supported thereon;

Figure '7 is a front elevational view of the filmholding member with a length of wide film supported thereon;

Figure 8 is a transverse sectional along line 88 of Figure '7;

Figure 9 is a fragmentary perspective view of the top of the upper portion of the daylight developing tank diagrammatically illustrating the manner in which photographic solutions are poured thereinto;

Figure 10 is a perspective view of the upper portion of the tank diagrammatically illustrating how photographic solutions may be poured out of the tank; and

Figure 11 is an exploded perspective view of the cap assembly.

Referring now in more detail and by reference characters to the drawing, which illustrates a preferred embodiment of the present invention,

view taken I A designates a daylight developing tank comprising a relatively thick oval-shaped base member I molded, cut, or otherwise formed of a synthetic plastic material selected for its resistance to the chemical action of photographic fluids. A number of such synthetic plastic materials are available under various trade names.

Adhesively mounted or otherwise rigidly fixed upon the upper face of the base member I in symmetrical or co-axial position in relation thereto is an upstanding, relatively thin-walled, tubular shell 2 of oval cross-sectional shape preferably formed from the same synthetic plastic material as the base i by the process of extrusion. It should be noted that the tubular shell 2 must be secured to the base 2 by a leakproof joint which is structurally strong, so that the base I and the shell 2 together form an open-topped elongated tank having long, flat side walls which are somewhat resilient and will yield slightly under squeezing pressure of the thumb andfingers of the user. It should also be noted in this connection that the base member 1 should be sufficiently larger in peripheral size than the tubular shell 2 and of sufficient weight to provide a suitable base for the structure, so that it may be placed in upright position upon a table or other similar structure without undue danger of accidental tipping or falling,

Provided for removable disposition within the open-top of the shell 2 is a closure member or cap B, which comprises an oval-shaped collar or rim-forming member 3 provided with a transversely extending bottom wall 4 adhesively or otherwise tightly secured across one end face of the collar 3 in peripheral registration therewith and provided at its opposite ends with circular apertures 5, 6. Extending transversely across the collar or rim-forming member 3 is a transverse partition I flush along its upper edge with the collar 3 and atits lower edge adhesively secured to the upper face of the bottom wall 4, thereby dividing the collar into two compart ments 0, 0, respectively containing the apertures 5, 5.

Adhesively secured upon the under face of the bottom wall 4 is an oblong-shaped spacing collar 8 geometrical in shape to, but somewhat smaller than, the collar 3 and bottom wall 4 and being provided with two axially aligned elongated slotlike apertures 9, I 0. Adhesively secured upon the under face of the spacing collar 8 is an inter mediate partition member H of the same peripheral size and shape as the spacing collar 6 and being disposed in peripheral registration therewith. The partition member ii is provided with two apertures l2, 13, which are located equidistantly on opposite sides of, and relatively close to the center of, the partition member H, so as to communicate respectively with the slots 3 9, l0, and yet be completely non-aligned with the apertures 5, 6. Also adhesively secured upon the under face of the partition member II is a second spacing collar l4 identical in size and shape with the Spacing collar 8 and disposed in peripheral registration therewith and having elongated slots l5, l6. Likewise adhesively secured upon the under face of the spacing collar 8 is a lower partition wall ll having the same peripheral size and shape as, and being in peripheral registration with, the spacing collar 14. The lower partition wall I1 is provided along its longitudinal axis with circular apertures l8, l9,

spaced outwardly a substantial distance from the center thereof, so as to be completely out of alignment with the apertures l2, l3, and more or less in alignment with the apertures 5, 6.

Preferably cemented upon, and extending around the outer faces of the spacing collars 8, 14, are continuous bands 20, 2|, formed of cork or other suitable gasketing material of sufficient thickness, so that the over-all peripheral size of the lower portion of the cap will be slightly larger than the internal diameter of the tubular shell 2.. tight -.cap-retentive and sealing engagement within the shell when the cap B is forced into place.

Provided for removable disposition within the shell. 2 is a film holder 22 consisting of an elongated rectangular sheet of thin plastic material which is resistant to photographic chemicals. The :film holder 22 is provided along its upper transverse margin'with a narrow U-shaped recess or slot 23, and along its lower transverse margin with a wide shallow recess or slot 2%. Along one longitudinal margin, the film holder 22 is inwardly cut away in the provision of a shallow longitudinal recess 25. Narrow film, such as 35 mm. film, for example, can be wrapped around the film holder 22, substantially as shown in Figure 6, and held in place thereon at its ends.

by conventional spring clips 25. Wide film can be looped around the film holder 22 and, at its ends, brought up equi-distantly on either side thereof for retention by a single film clip 26., as shown in Figure 7. The film holder 22 is of such size and dimension as will fit easily within the confines of the developing tank A, somewhat in the manner shown in dotted lines .in Figure 1.

In use, the'film holder 22 and the developing tank A are taken into a closet or placed under a heavy blanket and the roll of exposed film which is to be developed is unrolled and clipped upon the 'film'hol'cler 22. Because of th thin rectangular shape of the film holder 22, and the ease with which a section of rolled film may be unrolled and wrapped therearoun'd, and, finally, because of the readiness with which the clips 28 can be slipped inplace to retain the film upon the film holder '22, this entire operation can be very quickly and conveniently performed under almost any available conditions and "without recourse to a dark room. As has been above pointed out, the operation can be'very'convenien'tly performed beneath a blanket or other light-proof material. Once the film has been mounted upon'the film holder 2'2'f-the latter is slipped into the tank A and the cap B put in place. Thereupon, :the film and the film holder will'be enclosed within the light-proof interior of the tank A, "and the tank A may, therefore, be removed from beneath the blanket or the user may step out of the darkened closet in which the original loading operation lhas been performed.

The developer may then be poured into "the upright end of the cap .3, as diagrammatically The bands 20, 2|, will be forced into shown in Figure 9 and the tank may be gently shaken or agitated for the required length of time during which the film should be left within the developer solution. It has been found that agitation can be most efiectively accomplished by successively squeezing and releasing the side walls of the tank A, thereby causing the developer to rise and fall rapidly through a short distance. Thereupcn, the developer solution can be poured off by tilting the tank A, as shown in Figure 10, and the several washing and fixing solutions. can be poured into and out of the tank in successive order by substantially the same procedure until the development process has been completed. The cap B may thereupon be re-- moved and the film holder 22, together with the fully developed film, withdrawn. The film can be left upon the film holder 22 to dry, if desired, or can be removed for handling by other conventional drying means, if available.

It should be understood that changes and modifications in the form, construction, arrangement, and combination of the several parts of the daylight developing tank for photographic roll film may be made and substituted for those herein shown and described without departing from the nature and principle of my invention.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

1. A photographic developing device comprising, in combination, an elongated tank, and a tight fitting cap removably disposed across the top of the tank, said cap being provided with three spaced partitions, a transverse partition providing two sets of three aligned comp'art ments, each of the spaced partitions having apertures for providing communication between the compartments, said apertures being nonaligned to prevent light-leakage into the tank when the cap is in closure forming position and thereby affording two separate light-trapped passages through the cap, a collar extending upwardly from the uppermost partition surrounding both of the apertures thereof, and a transverse partition extending across the collar for separating said last-named apertures.

2. A photographic developing device comprising, in combination, an elongated tank and a tight fitting funnel-topped cap removably disposed across the top of the tank, said cap being provided with two sets of light-baffled apertures for permitting the introduction and removal of fiuids into and from the tank, and a partition extending transversely across its funnel top for separating the sets of apertures.

NATHAN WOLFF.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 748,964 Lutz Jan. 5, 1904 781,393 Brainerd Jan. 31, 1905 1,481,759 Sugiura et a1. Jan. 22, 1924 2,298,963 Naylor et al. Oct. 13, 1942 2,341,666 'Spota Feb. 15, 1944 FOREIGN PATENTS Number Country Date 449,567 7 Germany Sept. 23, 1927 5i5j388 Germany Mar. 2 1932 5902793 Germany Jan. 10, 1934 

